How to use jottings to help with subtraction: the first stages of moving towards written methods of subtraction.

Subtraction by decomposition is the way most adults are familiar with and is the way that children will ultimately use for larger numbers. Here is an introductory exploration of the idea.

Using the standard written method to subtract a 2-digit number from a 2-digit number.

Today we will look at the written method of subtraction, subtracting a 2-digit number from a 3-digit number including having to make an exchange.